1,; ( ; GYPSY AND P.KOWN-TAIL MOTHS. [Jan. 



the vigorous, thinning of the hitler and the cleaning and banding 

 of the remaining oaks, etc., followed up by a thorough spray- 

 ing of these trees, should suilice to hold the insects in check. 

 Where infested hard-wood growth adjoins pine w ..... Is, the thin- 

 ning and spraying of a protective belt, together with the band- 

 in-- of the pines up to a hundred feet from the border of the 

 woods, should be an effective control measure. 



A DISEASE OF THE GYPSY 

 It is a well-known law of nature that starvation induces 

 weakness, and weakness favors the inroads of disease. When 

 any species of animal life suffers from lack of sufficient or suit- 

 able food, that species becomes an easy victim to disease. This 

 principle applies as strongly to insects as to the higher forms 

 of life. There have repeatedly come under the observation of 

 the superintendent, in recent years, numerous cases where some- 

 what isolated gypsy moth colonies have completely consumed 

 the foliage available for food, and after many days of fruitless 

 wandering have been attacked and decimated by one or more 

 bacterial diseases. This was notably the case in the Lynn and 

 Saiigns woodland colonies during midsummer, 1907. While 

 these colonies were not isolated, and while the caterpillars on 

 their borders could still find food, in the central part of the 

 wide-spreading defoliated area no foliage was available for them, 

 and here the inroads of the disease were as remarkable as grati- 

 fying. W fie re the trees were banded with sticky materials to 

 prevent the a -cent of th e caterpillars, at their base could often 

 be f. nmd masses of the dead insects in quantities running as 

 high as half a bushel or more, while throughout this large colony 

 the bodie> of hundreds of dead in-vts could be seen hanging on 

 almost every tree. So notable and important was this unex- 

 pected a. i-tanee on the part of natural causes, that it seemed 

 worthy of scientific in\e.-t igai ion, particularly with the view of 

 determining if it were pos-ihle to propagate the disea-e, and use 

 it as an additional mean- for destroying the moth pests. To 

 thi- end we have fortunately secured the services of Prof. Her- 

 bert P. .lohn-.u of the I'liiversity of St. I.ouis, a man thor- 

 oughly qualified to make the ueceary invest i^ations. Although 



